| 摘要 |
PURPOSE:To stop runaway not detected by a failure detecting circuit without decreasing the number of ports usable for substantial control by providing a watchdog circuit in a microcomputer. CONSTITUTION:The microcomputer 10 is incorporated with the watchdog circuit 20 or the like constituted by a main body section 1a, a frequency abnormality detecting circuit 2 and a free-running multivibrator 3. When a reset signal is inputted from a reset terminal, an initializing program is executed only just after power-on. Then, the programs transfer to the execution of the main program and when this is finished, a signal is outputted to the circuit 20 and a monostable multivibrator 4, and a reset signal is outputted at each end of the main program. Even the runaway not detected is stopped by providing the circuit 20 in this way and outputting the reset signal at each end of the main program. |
